Option B is correct. Technical advancement leads to a shift in the PPF curve and it leads to long-run economic growth. For growth in an economy, they need to implement those policies which affects them to work out of their existing potential.
Converting idle land into farm land would promote potential growth. At point A, resources are underutilized. The point A will come on the PPF curve only when resources are fully utilized in the economy. There is no further growth in the economy thereafter.
draw the graph & label the points where they belong WIR With Graphing Questions - Clapter...